Method for satining a ring made of rigid material and jig therefor

ABSTRACT

Disclosed are a jig and a method for forming a satin surface on an outer peripheral surface of a ring made of a rigid material by processing the outer peripheral surface of the ring using a diamond bite in a state in which inner and outer peripheral surfaces of the ring do not represent a perfect roundness and a center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring. The method includes the steps of supporting both sides of the ring while rotating the ring, and processing the outer peripheral surface of the ring by using the diamond bite.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of satining a ring made of a rigid material and a jig therefor.

2. Description of the Prior Art

As generally known in the art, conventional rings are classified into rings containing precious metals, such as gold or silver made of a soft material, and inlaid rings having expensive jewels inlaid in a portion of an outer peripheral surface thereof.

Such conventional rings are made of soft materials, so that surfaces of the rings may be easily scratched. In addition, the conventional rings are so expensive that they cannot be extensively used as accessories.

In this regard, low-price rings capable of preventing surfaces thereof from being scratched have been developed.

Such low-price rings can be obtained through performing a series of processes of providing a powdered mixture containing at least 50 weight percent of tungsten carbide, which is a rigid material used for a watchband or a bearing, compressing and sintering the powdered mixture through powder metallurgy so as to form a annular shape, and grinding/polishing the metallic material in the form of the ring.

Since the rings are made of the rigid materials, the rings have rigid surfaces, so that the surfaces of the rings can be prevented from being scratched. In addition, the rings are highly polished through the satin process using a grinding wheel, so that the rings have superior luster characteristics. For this reason, the rings are favorably commented in foreign countries.

However, since the outer peripheral surface of the conventional ring made of the rigid material is grinded/polished by means of the grinding wheel, of which an outer peripheral surface is attached with diamond powder and has a rough surface, so that the outer peripheral surface of the conventional ring has an irregular surface roughness even through it glitters. Thus, the conventional ring cannot generate rainbow colors because the external light reflected from the outer peripheral surface of the conventional ring is subject to diffuse reflection, thereby degrading the commercial value of the ring. In addition, the conventional ring will be easily stained with grime in use, due to the irregular surface roughness of the outer peripheral surface of the conventional ring. Such grime may not be easily removed from the ring.

In order to solve the above problem, it is necessary to perform the satin process, in which the outer peripheral surface of the ring made of the rigid material is processed by means of a diamond bite, other than the grinding wheel. According to the satin process, in which the diamond bite linearly moves while a workpiece, that is, the ring made of the rigid material is being rotated, a micro stripe pattern which is not visible to the naked eyes, is uniformly formed on the outer peripheral surface of the ring.

Such a micro stripe pattern uniformly formed on the outer peripheral surface of the ring may generate visible rainbow colors when it is exposed to the external light, thereby improving the commercial value of the ring while facilitating removal of grime from the ring.

However, since the conventional ring is fabricated through the compressing and sintering processes, the outer and inner peripheral surfaces of the ring do not represent the perfect roundness and the center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring. Accordingly, when the satin process is performed with respect to the outer peripheral surface of the ring by linearly moving the diamond bite at a low speed while rotating the ring in a state in which the ring is fixedly supported by means of a chuck inserted into the ring, the ring being rotated may vibrate so that the ring is subject to great impact when it makes contact with the diamond bite, causing the breakage of the ring.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a method for satining an outer peripheral surface of a ring using a diamond bite by linearly moving the diamond bite with respect to the ring being rotated, even if outer and inner peripheral surfaces of the ring do not represent the perfect roundness and the center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring.

In order to accomplish the above object, the present invention provides a method for forming a satin surface on an outer peripheral surface of a ring made of a rigid material by processing the outer peripheral surface of the ring using a diamond bite in a state in which inner and outer peripheral surfaces of the ring do not represent a perfect roundness and a center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring, the method comprising the steps of: supporting both sides of the ring while rotating the ring; and processing the outer peripheral surface of the ring by using the diamond bite.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating a typical lathe; and

FIG. 2 is a view illustrating a jig installed in a lathe shown in FIG. 1 according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a jig used for satining a ring made of a rigid material according to a preferred embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a typical lathe 100 used for machining a workpiece.

The lathe 100 mainly includes a bed 10, a headstock 20, a tailstock 30, a carriage 40 and a tool post 50.

As shown in FIGS. 1 and 2, one end of a first jig 100 is inserted into a chuck 22 of the headstock 20 in order to support one side of the ring, and a second jig 200 is fitted around a tail spindle 31 of the tailstock 30 so as to support the other end of the ring. Since the chuck 22 and the tail spindle 31 are concentrically aligned along the rotational center line O, the first jig 100 fixed by means of the chuck 22 and the second jig 200 fixed by means of the tail spindle 31 are aligned along the same rotational center line O.

The first jig 100 has a tubular shape. Since one end of the first jig 100 is fixedly supported in the chuck 22, the first jig 100 may rotate together with the chuck 22 when the chuck 22 rotates.

A first chamfering section 101 is formed at a front end portion of the first jig 100 so as to allow the first jig 100 to easily make contact with one side of the ring R.

A second chamfering section 201 is formed at a front end portion of the second jig 200 so as to allow the second jig 200 to easily make contact with the other side of the ring R. In addition, a flange 202 is provided at an outer peripheral surface of a middle part of the second jig 200 and a stepped portion 203 is formed in the inner peripheral surface of the second jig 200. The stepped portion 203 makes contact with a tapered portion 31 a provided at the front end portion of the tail spindle 31, so that the stepped portion 203 is also tapered corresponding to the tapered portion 31 a. A rear end portion of the second jig 200 is inserted into a bearing 60 fitted around the tail spindle 31. In addition, the flange 202 of the second jig 200 makes contact with a front end portion of the bearing 60, so that the flange 202 is biased toward the first jig 100 by means of the bearing 60.

Hereinafter, the satin process performed with respect to the ring by means of the lathe having the first and second jigs 100 and 200 will be described.

First, the first jig 100 is installed in the chuck 22 and the second jig 200 is fitted around the tail spindle 31 with the bearing 60 being interposed between the second jig 200 and the tail spindle 31.

After that, in a state in which the first chamfering section 101 formed at the front end portion of the first jig 100 makes contact with one side of the ring, the tail spindle 31 moves forward so as to allow the second chamfering section 201 formed at the front end portion of the second jig 200 to make contact with the other side of the ring. When the second chamfering section 201 of the second jig 200 makes contact with the other side of the ring R, which is made of the rigid material and undergone compressing and sintering processes, the ring R is fixedly supported by means of the first and second jigs 100 and 200.

Then, the chuck 22 is rotated together with the first jig 100. Accordingly, the ring R making contact with both first and second jigs 100 and 200 is also rotated. Since the second jig 200 is fitted around the tail spindle 31 while being inserted into the bearing 60 and the flange 202 of the second jig 200 makes contact with the front surface of the bearing 60, the second jig 200 can be rotated together with the ring R while stably supporting the other side of the ring R.

After that, the diamond bite B installed in a feed unit 50 moves forward so as to perform the cutting process with respect to the outer peripheral surface of the ring R being rotated. Thus, a satin surface is formed on the outer peripheral surface of the ring R by means of the diamond bite B.

According to the present invention, since both sides of the ring R are supported by means of the first and second jigs 100 and 200 aligned along the same rotational center line O, the ring R may rotate about the rotational center line O even if the inner and outer peripheral surfaces of the ring R do not form the concentric circles. Accordingly, the satin surface can be stably formed on the outer peripheral surface of the ring R without applying great impact to the ring R when the outer peripheral surface of the ring R is processed by means of the diamond bite B.

It is also possible to form an annular groove on the outer peripheral surface of the ring by using the method and the jig according to the present invention.

As described above, according to the present invention, the outer peripheral surface of the ring made of a rigid material is processed by means of the diamond bite, so that the satin surface can be formed on the outer peripheral surface of the ring, thereby improving the commercial value of the ring while. In addition, grime adhering to the outer peripheral surface of the ring can be easily removed.

Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A method for forming a satin surface on an outer peripheral surface of a ring made of a rigid material by processing the outer peripheral surface of the ring using a diamond bite in a state in which inner and outer peripheral surfaces of the ring do not represent a perfect roundness and a center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring, the method comprising the steps of: supporting both sides of the ring while rotating the ring; and processing the outer peripheral surface of the ring by using the diamond bite.
 2. The method as claimed in claim 1, further comprising the steps of: interposing the ring between a first jig and a second jig, in which one end of the first jig is inserted into a chuck of a lathe and the second jig is fitted around a tail spindle, and rotating the ring by means of a rotational force of the chuck while supporting both sides of the ring using the first and second jigs; and moving the diamond bite, which is installed in a feed unit of the lathe, toward the outer peripheral surface of the ring being rotated, thereby processing the outer peripheral surface of the ring, wherein the first and second jigs are aligned along a same rotational center line.
 3. A jig assembly unit used for forming a satin surface on an outer peripheral surface of a ring by processing the outer peripheral surface of the ring using a diamond bite installed in a feed unit of a lathe in a state in which inner and outer peripheral surfaces of the ring do not represent a perfect roundness and a center of the outer peripheral surface of the ring is offset from that of the inner peripheral surface of the ring, the jig assembly comprising: a first jig fixedly inserted into a chuck of a headstock in such a manner that a front end portion of the first jig is able to support one side of the ring; and a second jig fitted around a tail spindle of a tailstock in such a manner that a front end portion of the second jig is able to support the other side of the ring, wherein the first and second jigs are aligned along a rotational center line of the chuck or the tail spindle, the first jig has a tubular shape and a first chamfering section is formed on the front end portion of the first jig, and a second chamfering section is formed on the front end portion of the second jig.
 4. The jig assembly as claimed in claim 3, wherein a flange is provided at an outer peripheral surface of a middle part of the second jig, a stepped portion is formed at an inner peripheral surface of the second jig such that the stepped portion makes contact with a tapered portion formed at a front end of the tail spindle, the stepped portion is tapered corresponding to the tapered portion of the tail spindle, a rear end portion of the second jig is inserted into a bearing fitted around the tail spindle, and the flange of the second jig makes contact with a front end portion of the bearing, so that the flange is biased toward the first jig by means of the bearing. 